Data Zone
Justification of Red List category
This species is listed as Near Threatened because its lowland forest habitat is suffering conversion to oil palm plantations and logging, which is likely to be causing a moderately rapid population decline.
Population justification
No population density estimates are available, but the population size is suspected to be greater than 10,000 mature individuals (Buchanan et al. 2008; Davis et al. 2018). The species has been recorded frequently during surveys on New Britain, although the frequent records in hill forests may have resulted from the species's tendency to fly large distances, and may obscure a dependency on coastal and riparian habitats (Davis et al. 2018).
The species has a large range, with an estimated 39,000 km2 of tree cover with at least 50% canopy cover within its range in 2010, although this figure is likely to include oil palm plantations (Global Forest Watch 2021). Based on the first quartile and median recorded densities of congeners (14.5 and 38 individuals/km2, respectively), the area of tree cover stated above, and assuming that 10-25% of available tree cover is occupied, the population size is tentatively suspected to fall in the range 57,000 - 373,000 individuals, roughly equating to 38,000 - 249,000 mature individuals.
The subpopulation structure is not known, but the species has a fairly high dispersal ability, and occurs on a large number of islands. The number of subpopulations is suspected to fall within the range 2-20.
Trend justification
Over 19 years from 2000 to 2019, approximately 9.6% of tree cover with at least 50% canopy cover was lost from across the species's range (Global Forest Watch 2021). Extrapolating over 21 years (three generations), an estimated 11% of tree cover was lost from the species's range, and 12% is suspected to be lost over the next three generations. However, the estimated rate of tree cover loss was higher over the past few years, particularly in 2015 (Global Forest Watch 2021). Based on the rate of tree cover loss over the period 2014-2019 alone, it may be suspected that 20% of tree cover will be lost over the next three generations.
The impact of forest loss and degradation on the species is not known, and the species may experience declines as a result of forest degradation in addition to forest loss (Buchanan et al. 2008), although it has been recorded in high numbers in degraded forest (Davis et al. 2018). The population is therefore suspected to have undergone a reduction of 6-16% over the past three generations, and it is suspected to undergo a reduction of 7-25% over the next three generations.
Ducula subflavescens is endemic to the Bismarck Archipelago, Papua New Guinea, including Long Island, Umboi, New Britain, Lolobau, Watom, Duke of York, New Ireland, Lavongai, and the Admiralty Islands (including Manus, Lou and Nauna).
It is a nomadic forest species, often seen in lowland forest but recorded sporadically up to 940 m on New Britain (Gilliard and LeCroy 1967; Finch and McKean 1987; D. Bishop in litt. 1996, 1999; Dutson 2011) and 560 m on New Ireland and across Manus (Dutson 2011). Surveys in New Britain found that the species was fairly common in lowland and hill forest, common in degraded hill forest and rare in degraded lowland forest (Davis et al. 2018), although the frequency of records in the degraded hill forests may result from the species's tendency to fly large distances, and may obscure a dependency on coastal and riparian habitats (Gibbs et al. 2001; Davis et al. 2018). The species was absent from oil palm plantations (Davis et al. 2018).
Most lowland forest and especially coastal forest in this species's range is threatened by logging and conversion to oil palm plantations. In 2002, all forest in New Ireland and West New Britain and most forest in East New Britain and Manus was allocated for industrial forestry, and New Britain alone accounted for approximately half of Papua New Guinea's timber exports (Bun et al. 2004). Regulations on the frequency of re-logging areas are being ignored (Nelson et al. 2014). Many areas of lowland forest in New Britain have been converted to oil palm plantations (Swartzendruber 1993; Buchanan et al. 2008). Much of the Bismarck Archipelago has been allocated as Special Agricultural Business Lease (SABL) areas, which would permit conversion to oil palm plantations. However, many of these areas appear to be unsuitable for oil palm, suggesting that they may be in place to facilitate commercial logging, under the pretext of oil palm development (Nelson et al. 2014; Bryan et al. 2015). Nevertheless, conversion to oil palm is likely to continue slowly in the region (Nelson et al. 2014). On New Britain, 13.8% of forest within the species elevational range was cleared between 1990 and 2000 (Buchanan et al. 2008). Since then, the rate of deforestation apparently slowed (B. Beehler in litt. 2016; Bryan et al. 2015). From 2002 to 2014, around 7.4% of forest on New Britain; 9.1% of forests on Manus; and 7.6% of forests on New Ireland, were cleared or logged (Bryan et al. 2015). On New Ireland, most lowland forest was lost before 1989, and the area converted to oil palm has been much smaller (Davis et al. 2018).
It appears not to be threatened by hunting (G. Dutson pers. obs. 1997-1998).
Conservation Actions Underway
It occurs in a number of protected areas.
Conservation Actions Proposed
Carry out surveys across its range to estimate population density and gain an estimate of its population size. Continue to monitor trends in forest loss in the region. Research its tolerance of degraded forest. Monitor populations in a number of primary forest and degraded forest sites across the islands.
Identify and effectively protect a network of reserves, including some containing large areas of unlogged lowland forest and some large community-based conservation areas.
Text account compilers
Wheatley, H.
Contributors
Beehler, B.M., Bishop, K.D., Davis, R.A., Derhé, M., Dutson, G., Mahood, S. & O'Brien, A.
Recommended citation
BirdLife International (2024) Species factsheet: Yellowish Imperial-pigeon Ducula subflavescens. Downloaded from
https://datazone.birdlife.org/species/factsheet/yellowish-imperial-pigeon-ducula-subflavescens on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/11/2024.